Construction method and system of whole-process simulation model of steam power system

Abstract

The invention discloses a construction method and system for a whole-process simulation model of a steam power system. The construction method comprises the steps that multiple thermodynamic models are constructed based on multiple thermodynamic properties of water and steam; building a mathematical model of various unit equipment of the steam power system based on various thermodynamic models; determining all target unit devices and connection relations included in the target steam power system to be simulated, and all target types to which all the target unit devices belong; determining a simulation calculation sequence of each target unit device based on the connection relationship; and according to a simulation calculation sequence, performing simulation calculation on each target unit device by utilizing the mathematical model of each target type unit device and the value of the set input parameter of each target unit device to obtain the value of the correspondingly set output parameter until all target unit devices are subjected to simulation calculation to obtain a full-process simulation model. The embodiment of the invention can be suitable for construction of the whole-process simulation model of the steam power system of any structure, and support is provided for development of subsequent work.

Description

Technical Field

[0001] This document relates to model construction technology, particularly to a method and system for constructing a full-process simulation model of a steam power system. Background Art

[0002] A steam power system converts primary energy (such as fuels like coal, natural gas, refinery dry gas, etc.) into secondary energy (such as steam, electricity, etc.), provides the necessary steam for heating and tracing of process streams, provides the necessary power for rotating equipment such as pumps and compressors, and simultaneously co-produces a portion of electricity. It is an essential part of enterprises such as refineries and petrochemical plants. The steam power system includes steam generation, transportation, utilization, condensate recovery, as well as parts such as water supply, fuel supply, and power supply that are closely related to the steam power system.

[0003] The steam power system has a complex structure, numerous equipment, multiple pipe network pressure levels, usually a large amount of steam desuperheating and pressure reduction, steam venting existing, large heat losses in the pipe network, and room for improvement in energy conversion and transportation efficiency. It consumes a large amount of energy and resources during its operation, resulting in high operating costs. Additionally, with the improvement of crude oil processing capacity, product quality upgrading, and product portfolio changes with the market in enterprises such as refineries and petrochemical plants, the flexibility of the steam power system needs to be enhanced. The steam power system is a weak link in current energy conservation, efficiency improvement, and emission reduction, with great potential for optimization. For operations optimization and adjustment, technical renovation and measure plan calculation, operating cost prediction, operating level evaluation, etc. of the steam power system, accurate simulation calculations of the steam power system are required. However, the steam power system is too complex, and existing related technologies lack methods for accurately simulating it. Summary of the Invention

[0004] This application provides a method and system for constructing a full-process simulation model of a steam power system, which can be applicable to the construction of full-process simulation models of steam power systems with any structure, thereby providing model tool support for subsequent operations optimization and adjustment, technical renovation and measure plan calculation, operating cost prediction, operating level evaluation, etc.

[0005] In the first aspect of this application, a method for constructing a full-process simulation model of a steam power system is provided, including: constructing multiple thermodynamic models of water and steam based on multiple thermodynamic properties of water and steam;

[0006] constructing mathematical models of various unit equipment of the steam power system based on multiple thermodynamic models of water and steam; wherein, the mathematical model of each type of unit equipment includes: at least one set of set input parameters and at least one set of set output parameters corresponding to at least one set of set input parameters, and the mathematical model of each type of unit equipment is used to calculate the value of a corresponding set of output parameters according to the value of one set of input parameters;

[0007] Determine all target unit devices and connection relationships included in the target steam power system to be simulated, as well as all target types to which all target unit devices belong;

[0008] Based on the connection relationship, determine the simulation calculation order of each target unit device in the target steam power system;

[0009] According to the obtained simulation calculation order, use the mathematical models of unit devices of each target type and the values of input parameters set for each target unit device to simulate and calculate each target unit device, and obtain the values of output parameters set for each target unit device accordingly, until all target unit devices are simulated and calculated to obtain the full-process simulation model of the target steam power system.

[0010] In the second aspect of the present application, a system for constructing a simulation model of a steam power system is provided, including: a memory and a processor, where the memory is used to store an executable program;

[0011] The processor is used to read and execute the executable program to implement the method for constructing the full-process simulation model of the steam power system in the above embodiments.

[0012] The first module is used to construct a thermodynamic model for calculating various thermodynamic properties of water and steam, as well as a mathematical model for complex process calculation; the second module is used to construct mathematical models of various types of unit devices in the steam power system based on the thermodynamic model and the characteristics of the unit devices, etc.; the third module is used to determine the simulation calculation order of the steam power system to be simulated, and provide specific input interfaces for input parameters and output parameters set for each unit device, as well as functions such as full-process simulation calculation. A computer program product is provided in cooperation with the system, including a computer program, and when the program is executed by the processor, the steps of the method for constructing the simulation model of the steam power system in the first aspect or any possible implementation manner of the first aspect are implemented.

[0013] Compared with the related technologies, the present application includes: constructing mathematical models of various unit devices of a steam power system based on multiple thermodynamic models of water and steam; wherein, the mathematical model of each type of unit device includes: at least one set of set input parameters and at least one set of set output parameters corresponding to at least one set of set input parameters, and the mathematical model of each type of unit device is used to calculate the value of a corresponding set of output parameters according to the value of one set of input parameters; determining all target unit devices and connection relationships included in the target steam power system to be simulated, as well as all target types to which all target unit devices belong; determining the simulation calculation order of each target unit device in the target steam power system based on the connection relationship; according to the obtained simulation calculation order, using the mathematical models of unit devices of each target type and the values of the set input parameters of each target unit device to simulate and calculate each target unit device, obtaining the values of the corresponding set output parameters of each target unit device, until all target unit devices are simulated and calculated, obtaining the full-process simulation model of the target steam power system. The embodiments of the present application can be applied to the construction of the full-process simulation model of a steam power system with any structure, thereby providing model tool support for subsequent operation optimization and adjustment, technical renovation and measure plan accounting, operation cost prediction, operation level evaluation, etc.

[0014] The present application can construct the full-process simulation model of the steam power system to be simulated and calculated by means of the pre-constructed mathematical models of unit devices and the steam power system simulation calculation order method according to the process of the steam power system to be simulated and calculated and the unit devices included therein, thereby providing model tool support for subsequent operation optimization and adjustment, technical renovation and measure plan accounting, operation cost prediction, operation level evaluation, etc.

[0015] Other features and advantages of the present application will be described in the subsequent specification, and, in part, will become apparent from the specification, or will be understood by implementing the present application. Other advantages of the present application can be realized and obtained through the solutions described in the specification and the drawings.

[0016] Other features and advantages of the present application will be described in the subsequent specification, and, in part, will become apparent from the specification, or will be understood by implementing the present application. Other advantages of the present application can be realized and obtained through the solutions described in the specification and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The drawings are used to provide an understanding of the technical solutions of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solutions of the present application and do not constitute a limitation to the technical solutions of the present application.

[0018] Figure 1 It is a schematic flowchart of a method for constructing a full-process simulation model of a steam power system provided by an embodiment of the present application;

[0019] Figure 2 A schematic structural diagram of a steam power system provided by an embodiment of the present application. Detailed implementation manners

[0020] This application describes multiple embodiments, but the description is exemplary rather than restrictive, and it will be obvious to those of ordinary skill in the art that there can be more embodiments and implementation solutions within the scope covered by the embodiments described in this application. Although many possible feature combinations are shown in the drawings and discussed in the detailed implementation manners, many other combination ways of the disclosed features are also possible. Unless specifically restricted, any feature or element of any embodiment can be combined with any other feature or element in any other embodiment, or can replace any other feature or element in any other embodiment.

[0021] This application includes and contemplates combinations with features and elements known to those of ordinary skill in the art. The embodiments, features, and elements disclosed in this application can also be combined with any conventional features or elements to form unique inventive solutions defined by the claims. Any feature or element of any embodiment can also be combined with features or elements from other inventive solutions to form another unique inventive solution defined by the claims. Therefore, it should be understood that any feature shown and / or discussed in this application can be implemented alone or in any suitable combination. Therefore, except for the limitations made according to the appended claims and their equivalent replacements, the embodiments are not subject to other limitations. In addition, various modifications and changes can be made within the scope of protection of the appended claims.

[0022] In addition, when describing representative embodiments, the specification may have presented the method and / or process as a specific sequence of steps. However, to the extent that the method or process does not depend on the specific order of the steps described herein, the method or process should not be limited to the specific order of the steps described. As will be understood by those of ordinary skill in the art, other step orders are possible. Therefore, the specific order of the steps set forth in the specification should not be construed as a limitation on the claims. In addition, the claims directed to the method and / or process should not be limited to performing their steps in the order written, and those skilled in the art can easily understand that these orders can be changed and still remain within the spirit and scope of the embodiments of this application.

[0023] A steam power system converts primary energy sources (such as fuels like coal, natural gas, and refinery dry gas) into secondary energy sources (such as steam and electricity), provides the necessary steam for heating and tracing process streams, and provides the necessary power for rotating equipment such as pumps and compressors. At the same time, it co-produces a certain amount of electricity and is an essential part of enterprises such as refining and chemical industries. The steam power system includes steam generation, transportation, utilization, condensate recovery, as well as parts such as water supply, fuel supply, and power supply that are closely related to the steam power system.

[0024] The steam power system has a complex structure, numerous equipment, and multiple pipeline pressure grades. The amount of steam desuperheating and pressure reduction is usually large, steam venting exists, the heat loss of the pipeline network is large, and the energy conversion and transportation efficiency need to be improved. It consumes a large amount of energy and resources during its operation, resulting in high operating costs. In addition, with the improvement of the crude oil processing capacity, product quality upgrade, and product plan change with the market in enterprises such as refining and chemical industries, the flexibility of the steam power system needs to be improved. The steam power system is a weak link in current energy conservation, efficiency improvement, and emission reduction, and has great potential for optimization. For the operation optimization and adjustment of the steam power system, the calculation of technical renovation and improvement measures, the prediction of operating costs, and the evaluation of operating levels, etc., accurate simulation calculations of the steam power system are required. However, the steam power system is too complex, and the relevant technologies lack methods for accurate simulation.

[0025] The embodiment of this application provides a method for constructing a full-process simulation model of a steam power system, as Figure 1 shown, including:

[0026] Step 101: Construct various thermodynamic models of water and steam based on various thermodynamic properties of water and steam;

[0027] Step 102: Construct mathematical models of various types of unit equipment in the steam power system based on various thermodynamic models of water and steam; among them, the mathematical model of each type of unit equipment includes: at least one set of set input parameters and at least one set of set output parameters corresponding to at least one set of set input parameters, and the mathematical model of each type of unit equipment is used to calculate the value of a corresponding set of output parameters according to the value of one set of input parameters;

[0028] Step 103: Determine all target unit equipment and connection relationships included in the target steam power system to be simulated, as well as all target types to which all target unit equipment belong;

[0029] Step 104: Determine the simulation calculation order of each target unit equipment in the target steam power system based on the connection relationship;

[0030] Step 105: According to the obtained simulation calculation sequence, use the mathematical models of the target type unit devices and the values of the input parameters set for each target unit device to simulate and calculate each target unit device, and obtain the values of the output parameters set for each target unit device until all target unit devices are simulated and calculated, so as to obtain the full-process simulation model of the target steam power system.

[0031] The method for constructing the full-process simulation model of the steam power system provided by the embodiment of the present application can, according to the process of the steam power system to be simulated and calculated and the unit devices included therein, with the help of the pre-constructed mathematical models of the unit devices and the steam power system simulation calculation sequence method, construct the full-process simulation model of the steam power system to be simulated and calculated, thereby providing model tool support for subsequent operation optimization and adjustment, technical renovation and measure plan accounting, operation cost prediction, operation level evaluation, etc.

[0032] Exemplarily, the thermodynamic properties of water and steam are constructed according to the formula "Industrial Use Calculation Formula 1997 of the International Association for the Properties of Water and Steam" (abbreviated as IAPWS-IF97 formula) provided by the "International Association for the Properties of Water and Steam". The thermodynamic properties of water and steam include: enthalpy of water, entropy of water, enthalpy of steam, entropy of steam, density of steam, saturation pressure of water, saturation temperature of water, saturation pressure of steam, saturation temperature of steam, temperature of water, and temperature of steam.

[0033] In an exemplary example, the method further includes:

[0034] Determine various thermodynamic properties of the water and steam, and construct various thermodynamic models of the water and steam based on the obtained various thermodynamic properties;

[0035] In an exemplary example, the thermodynamic properties include: enthalpy of water, entropy of water, enthalpy of steam, entropy of steam, density of steam, saturation pressure of water, saturation temperature of water, saturation pressure of steam, saturation temperature of steam, temperature of water, and temperature of steam.

[0036] In an exemplary example, the constructing various thermodynamic models of the water and steam based on various thermodynamic properties of the water and steam includes: calculating the enthalpy of water according to the temperature and pressure of water; calculating the entropy of water according to the temperature and pressure of water; calculating the enthalpy of vapor according to the temperature and pressure of steam; calculating the entropy of vapor according to the temperature and pressure of steam; calculating the density of vapor according to the temperature and pressure of steam; calculating the saturation pressure of water or steam according to the temperature; calculating the saturation temperature of water or steam according to the pressure; calculating the temperature of water according to the pressure and enthalpy of water; calculating the temperature of steam according to the pressure and enthalpy of steam; calculating the temperature of water according to the pressure and entropy of water; calculating the temperature of steam according to the pressure and entropy of steam.

[0037] In an exemplary instance, the various types of unit devices include: header unit devices and non-header unit devices.

[0038] In an exemplary instance, the header unit devices include: water / steam headers, fuel headers, and power headers.

[0039] In an exemplary instance, the non-header unit devices include: steam boilers, steam turbines, pumps, desuperheating and pressure reducing valves, pressure reducing valves, deaerators, generator sets, pump sets, drive sets, heaters, coolers, heat exchangers, and flash drums.

[0040] Exemplarily, the drive set includes: 2 power sources and 1 corresponding driven device, the pump set includes: multiple pumps and power sources corresponding to each pump one by one, the power sources include: motors or steam turbines, and the driven devices include: pumps or compressors.

[0041] In an exemplary instance, when the unit device is a steam boiler, steam turbine, or pump, the mathematical model corresponding to the unit device is generated based on the material balance model, energy balance model, and efficiency calculation model of the unit device;

[0042] When the unit device is any one of the following: desuperheating and pressure reducing valve, deaerator, generator set, pump set, drive set, heater, cooler, heat exchanger, the mathematical model corresponding to the unit device is generated based on the material balance model and energy balance model of the unit device;

[0043] When the unit device is a flash drum, the mathematical model corresponding to the unit device is generated based on the material balance model, energy balance model, and phase equilibrium model of the unit device;

[0044] When the unit device is a water / steam header, the mathematical model corresponding to the unit device is generated based on the material balance model of the unit device;

[0045] When the unit device is a fuel header or power header, the mathematical model corresponding to the unit device is generated based on the energy balance model of the unit device;

[0046] In an exemplary instance, the material balance model of the unit device is constructed based on the material balance principle; the energy balance model of the unit device is constructed based on the law of conservation of energy and according to one or more thermodynamic property models of the enthalpy of water, enthalpy of steam, temperature of water, and temperature of steam; the efficiency calculation model of the unit device is based on the chemical engineering principles and chemical engineering thermodynamic equations of the unit device, and is constructed according to various thermodynamic properties including the enthalpy of water, entropy of water, enthalpy of steam, entropy of steam, density of steam, saturation pressure of water, temperature of water, and temperature of steam.

[0047] In an exemplary instance, determining the simulation calculation order of each target unit device in the target steam power system based on the connection relationship specifically includes:

[0048] First, according to the connection relationship of the steam power system, determine the simulation calculation order of the water / steam header in the forward or reverse order of the water / steam flow direction into the water / steam header, and associate the material balance input and output parameters of the steam header with the output or input related parameters of each target unit device connected thereto;

[0049] Then, determine the simulation calculation order of the fuel header in the forward or reverse order of the fuel flow direction into the fuel header, and associate the energy balance input and output parameters of the fuel header with the output or input related parameters of each target unit device connected thereto;

[0050] Next, determine the simulation calculation order of the power header in the forward or reverse order of the current flow direction into the power header, and associate the energy balance input and output parameters of the power header with the relevant output or input parameters of each target unit device connected thereto;

[0051] Then, determine the simulation calculation order of various headers and the target unit devices directly connected to various headers according to the calculation orders of the water / steam header, fuel header, and power header;

[0052] Finally, according to the simulation calculation orders of various headers and the target unit devices directly connected to various headers, determine the simulation calculation order of other target unit devices in the forward or reverse order of the process flow to obtain the simulation calculation orders of all target unit devices in the whole process of the target steam power system; wherein, the forward or reverse order is determined according to actual calculation requirements.

[0053] In an exemplary instance, the simulation calculation orders of the fuel header and the power header can be changed, that is, the fuel header can be simulated first and then the power header, or the power header can be simulated first and then the fuel header;

[0054] Exemplarily, according to the obtained simulation calculation order, using the mathematical models of each target type unit device and the values of the input parameters set for each target unit device to simulate each target unit device, and obtaining the values of the output parameters set for each target unit device until all target unit devices are simulated to obtain the full-process simulation model of the target steam power system, specifically includes:

[0055] First, according to the process of the target steam power system, based on the material balance of each water / steam header, the input and output of each water / steam mass flow rate of each water / steam header are respectively associated with the output of the water / steam mass flow rate of each target unit device connected thereto or the input parameter of the water / steam mass flow rate of each target unit device connected thereto;

[0056] Then, according to the process of the target steam power system, based on the energy balance of each fuel header, the input and output of each energy flow of each fuel header are respectively associated with the output of the energy flow of each target unit device connected thereto or the input parameter of the energy flow of each target unit device connected thereto;

[0057] Finally, according to the process of the target steam power system, based on the energy balance of each power header, the input and output of each energy flow of each power header are respectively associated with the output of the energy flow of each target unit device connected thereto or the input parameter of the energy flow of each target unit device connected thereto.

[0058] In an exemplary example, after obtaining the full-process simulation model of the target steam power system, it further includes:

[0059] Calculating the water consumption, fuel consumption, and power consumption of the target steam power system according to the full-process simulation model;

[0060] Calculating the fuel and power cost of the target steam power system according to the unit price of water, unit price of fuel, unit price of power, and the water consumption, fuel consumption, and power consumption of the target steam power system;

[0061] Calculating the carbon emission of the target steam power system according to the carbon emission factor and the water consumption, fuel consumption, and power consumption of the target steam power system.

[0062] In the method for constructing a full-process simulation model of a steam power system provided in the embodiments of the present application, strict material balance, energy balance, phase balance, and efficiency calculation mathematical models of steam boilers, desuperheaters, pressure reducing valves, deaerators, steam turbines, generators, pumps, pump groups, drive groups, heaters, coolers, heat exchangers, flash tanks, steam headers, fuel headers, and power headers are established according to relevant formulas such as chemical engineering thermodynamics and chemical engineering principles, as well as water / steam thermodynamic property calculation models.

[0063] Among them, the steam boiler, steam turbine, and pump contain three types of calculation equations for material balance, energy balance, and efficiency calculation. The efficiency of the steam boiler is calculated according to the steam production and efficiency curve equation of the current steam boiler. The efficiency of the steam turbine is calculated from the inlet temperature, pressure, outlet temperature, and pressure of the steam. The efficiency of the pump is calculated based on the effective power and shaft power of the pump; the desuperheater, pressure reducing valve, deaerator, generator set, pump, pump set, drive set, heater, cooler, and heat exchanger contain two types of equations for material balance and energy balance; the flash tank contains three types of equations for material balance, energy balance, and phase balance.

[0064] The steam header contains a material balance equation, and the fuel header contains a heat flow rate (product of fuel flow and corresponding lower heating value) balance equation (energy balance equation). The power header contains an energy balance equation.

[0065] The steam boiler, steam turbine, pump, desuperheater, pressure reducing valve, deaerator, and pressure reducing valve each have two different calculation modes, each of which is used under different conditions and corresponds to different set input parameters and set output parameters.

[0066] Taking the steam boiler as an example, the set input parameters of the first mode of the steam boiler mathematical model include steam production, steam temperature, steam pressure, inlet deaerated water temperature, inlet deaerated water pressure, blowdown rate, lower heating value of fuel, and boiler efficiency coefficient (fitted by a binomial containing two coefficients and one constant). The set output parameters include boiler efficiency, steam enthalpy, entropy of steam, deaerated water flow rate, deaerated water enthalpy, blowdown water flow rate, blowdown water temperature, blowdown water pressure, blowdown water enthalpy, fuel consumption, and fuel heat flow rate.

[0067] The set input parameters of the second mode of the steam boiler mathematical model include deaerated water flow rate, deaerated water temperature, deaerated water pressure, blowdown rate, steam temperature, steam pressure, lower heating value of fuel, and boiler efficiency coefficient (fitted by a binomial containing two coefficients and one constant). It is based on the boiler efficiency curve, and the corresponding efficiency is different under different loads. The set output parameters include: boiler efficiency, steam flow rate, steam enthalpy, entropy of steam, deaerated water enthalpy, blowdown water flow rate, blowdown water temperature, blowdown water pressure, blowdown water enthalpy, fuel consumption, and fuel heat flow rate.

[0068] Taking the steam turbine as an example, the set input parameters of the first mode of the steam turbine mathematical model include: shaft work demand, steam inlet temperature, steam inlet pressure, steam outlet temperature, and steam outlet pressure. The set output parameters include steam flow rate, inlet steam enthalpy, inlet steam entropy, outlet steam enthalpy, outlet steam entropy, isentropic efficiency, and polytropic efficiency.

[0069] The set input parameters of the mathematical model of the steam turbine in Mode 2 include: steam flow rate, steam inlet temperature, steam inlet pressure, steam outlet temperature, steam outlet pressure. The set output parameters include inlet steam enthalpy, inlet steam entropy, shaft work, outlet steam enthalpy, outlet steam entropy, isentropic efficiency, and polytropic efficiency.

[0070] Construct a thermodynamic model for calculating various thermodynamic properties of water and steam; based on the thermodynamic model of water and steam and the characteristics of unit equipment, etc., construct mathematical models of various types of unit equipment in the steam power system. Each type of unit equipment mathematical model includes one or more sets of set input parameters and corresponding set output parameters, as well as a mathematical model for calculating the corresponding set output parameters from the set input parameters; determine the flow process of the steam power system to be simulated and the unit equipment included; determine the simulation calculation sequence of the steam power system according to a specific calculation sequence method; use the mathematical models of various types of unit equipment and the values of the set input parameters of each unit equipment to simulate and calculate each unit equipment one by one to obtain the values of the set output parameters of each unit equipment until all unit equipment simulation calculations are completed, and finally construct a full-process simulation model of the steam power system according to the above method. Through the mathematical models of material balance, energy balance, phase balance, and efficiency calculation of unit equipment in this application, one or several calculation results of material balance, energy balance, phase balance, and efficiency of relevant unit equipment can be determined. Through the full-process simulation model of the steam power system, the material balance of the steam power system can be determined. Through the cost calculation model and carbon emission calculation model, the fuel cost and carbon emissions can be determined. Subsequently, an optimization model is established based on the full-process simulation model, which can optimize equipment load, equipment start-stop, etc., so as to realize the optimized operation of the steam power system, reduce fuel cost, reduce carbon emissions, and can also calculate the equipment operation efficiency, correct the steam / water balance, and assist in calibrating instruments, promoting a huge transformation of technicians' understanding of the system from qualitative to quantitative.

[0071] The embodiment of this application also provides a construction system of a full-process simulation model of a steam power system, including a memory and a processor;

[0072] The memory is used to save executable programs;

[0073] The processor is used to read and execute the executable program to implement the construction method of the full-process simulation model of the steam power system described in any of the above embodiments.

[0074] The embodiment of the present application also provides a construction system for a full - process simulation model of a steam power system. By using the above - mentioned methods for constructing thermodynamic properties, mathematical models, and simulation calculation sequences, etc., the system realizes strict simulation calculations for the steam power system and unit equipment, ensuring the reliability, accuracy, and operability of the methods of the present application, and realizing a huge transformation from qualitative to quantitative understanding of the system by technicians. Specifically, it includes:

[0075] The first module is used to construct a thermodynamic model for calculating the thermodynamic properties of water and steam, and a mathematical model for calculating complex processes, such as a boiler efficiency curve fitting model, a mathematical model for calculating the isentropic efficiency, polytropic efficiency of steam turbines, and other complex processes;

[0076] The second module is used to construct mathematical models for various unit equipment of the steam power system based on the thermodynamic model, mathematical models for complex process calculations, and the characteristics of unit equipment, etc., and encapsulate the models. Only by giving (or obtaining through association) the values of the set input parameters can the set output parameters be obtained. In applications, for the same type of unit equipment, there is no need to rebuild the model, and only the encapsulated model can be used, greatly improving the simulation efficiency.

[0077] The third module is used to determine the simulation calculation sequence of the steam power system to be simulated, and provide specific input interfaces for the set input parameters and output parameters of each unit equipment, as well as functions such as full - process simulation calculation. The third module includes:

[0078] The non - header - type unit equipment module: includes steam boilers, desuperheaters, pressure reducing valves, deaerators, steam turbines, generators, pumps, pump sets, drive sets, heaters, coolers, heat exchangers, flash tanks;

[0079] The header - type module: includes water / steam headers, fuel headers, power headers.

[0080] The fuel cost and carbon emission module: used to calculate the fuel cost and carbon emissions.

[0081] Embodiment 1

[0082] In a specific embodiment, as Figure 2 shown, the steam power system consists of a deaerator, deaerator water pumps, 4 steam boilers, 2 desuperheaters, 2 3.5MPa steam headers, 2 1.0MPa steam headers, 1 fuel header, 1 power header, 1 set of pump sets (including 4 motor - driven pumps and 2 steam - turbine - driven pumps), and 4 sets of drive sets. Based on the Figure 2 shown steam power system, using the constructed thermodynamic model of water and steam, mathematical models of various unit equipment, the full - process simulation calculation sequence method of the steam power system, and input data, etc., the model construction steps are as follows:

[0083] Step 1. According to the process of the steam power system and the unit equipment it contains, in this embodiment, the utility supply is calculated based on the utility requirements and the input parameters of the unit equipment. The simulation calculation order of various headers is determined in the reverse order of the process. The simulation calculation order of the water / steam headers is the 1.0 MPa steam 2# header, the 3.5 MPa steam 2# header, the 1.0 MPa steam 1# header, and the 3.5 MPa steam 1# header;

[0084] Step 2. Correlate the material balance feed, discharge of the water / steam headers and the output or input related parameters of each unit equipment connected thereto. Specifically, the input steam flow of the 1.0 MPa steam 2# header is correlated with the output steam flows of the 1.0 MPa steam 1# header, the 2# desuperheater, the 1# drive group, the 2# drive group, the 3# drive group, and the 4# drive group respectively. The output steam of the 1.0 MPa steam 2# header is determined as a fixed value according to the process requirements; the input steam flow of the 3.5 MPa steam 2# header is correlated with the output steam of the 3.5 MPa steam 1# header, and the output steam flows are correlated with the input steam flows of the 1.0 MPa steam 2# header, the 2# desuperheater, the 1# drive group, and the 2# drive group respectively; the input steam flow of the 1.0 MPa steam 1# header is correlated with the output steam flows of the 1# desuperheater and the pump group respectively, and the output steam flow is correlated with the input steam flow of the deaerator; the input steam flow of the 3.5 MPa steam 1# header is correlated with the outputs of the 1# steam boiler, the 3# steam boiler, the 4# steam boiler, and the 2# steam boiler respectively, and the output steam flows are correlated with the pump group and the 1# desuperheater respectively; the incoming electricity (output) of the fuel header is a calculated value, and the outgoing electricity (input) is correlated with the energy flows of the 1# steam boiler, the 3# steam boiler, the 4# steam boiler, and the 2# steam boiler respectively; the incoming electricity (output) of the power header is a calculated value, and the outgoing electricity (input) is correlated with the power consumption of the 1# drive group, the 2# drive group, and the pump group respectively;

[0085] Step 3. According to the simulation calculation order of various headers and the unit equipment directly connected to various headers, determine the simulation calculation order of other unit equipment in the reverse order of the process as the 1.0 MPa steam 2# header, the 2# desuperheater, the 1# drive group, the 2# drive group, the 3.5 MPa steam 2# header, the 1.0 MPa steam 1# header, the pump group, the 1# desuperheater, the 3.5 MPa steam 1# header, the 1# steam boiler, the 3# steam boiler, the 4# steam boiler, the 2# steam boiler, the fuel header, and the power header;

[0086] Step 4. Determine the simulation calculation sequence of other unit devices in reverse order according to the process, and form the simulation calculation sequence of each unit device in the whole process of the steam power system as follows: 1.0 MPa steam 2# header, 2# desuperheater and pressure reducer, 1# drive group, 2# drive group, 3.5 MPa steam 2# header, 1.0 MPa steam 1# header, pump group, 1# desuperheater and pressure reducer, 3.5 MPa steam 1# header, 1# steam boiler, 3# steam boiler, 4# steam boiler, 2# steam boiler, deaerating water pump, deaerator, fuel header, power header;

[0087] Step 5. Associate the input and output parameters of the unit devices directly connected to the non-header unit devices with the output or input parameters of the adjacent unit devices respectively. Specifically, the outlet water volume of the deaerating water pump is associated with the inlet deaerated water flow rates of the 1# - 4# steam boilers and the 1# - 2# desuperheaters and pressure reducers respectively, and the deaerated water volume of the deaerator is associated with the inlet water volume of the deaerating water pump;

[0088] Step 6. According to the calculation sequence of this specific embodiment and the process of the steam power system, call the pre-constructed mathematical models of the corresponding unit devices to select the appropriate calculation mode, and input specific values according to the set input parameter requirements. For those input parameters that are associated with the output parameters of other unit devices, there is no need to input, and they are obtained after the calculation of other unit devices is completed.

[0089] The input values and simulation calculation results of each unit device in this specific embodiment are shown in Tables 1 - 10 respectively. The input parameters of the non-header unit devices are manual input values or are obtained through association by simulating and calculating other unit devices and then through association.

[0090] Table 1 Simulation Results of Unit Devices of Steam Boiler Type

[0091]

[0092]

[0093] Table 2 Simulation Calculation Results of Unit Devices of Desuperheater and Pressure Reducer Type

[0094]

[0095] Table 3 Simulation Calculation Results of Unit Devices of Turbine Type (One of the Components of the Pump Group or Drive Group)

[0096]

[0097]

[0098] Table 4 Simulation Calculation Results of Unit Devices of Pump Group Type

[0099]

[0100] Table 5 Simulation Calculation Results of Unit Equipment in the Drive Group

[0101]

[0102] Table 6 Simulation Calculation Results of Unit Equipment in the Deaerator Class

[0103]

[0104] Table 7 Simulation Calculation Results of Unit Equipment in the Pump Class

[0105]

[0106] Table 8 Simulation Calculation Results of Unit Equipment in the Water / Vapor Header Class

[0107]

[0108]

[0109] Table 9 Simulation Calculation Results of Unit Equipment in the Fuel Header Class

[0110]

[0111] Table 10 Simulation Calculation Results of Unit Equipment in the Power Header Class

[0112]

[0113] Assuming that the prices of fuel, electricity, and demineralized water are 65 yuan / GJ, 550 yuan / (MW·h), and 6 yuan / t respectively, the fuel and power cost of the steam power system can be calculated to be 73,940.85 yuan per hour. Based on the carbon emission factors of various utilities, etc., the carbon emissions corresponding to the utility consumption can be calculated.

Claims

1. A method for constructing a full-process simulation model of a steam power system, characterized in that The method includes: Constructing various thermodynamic models of water and steam based on various thermodynamic properties of water and steam; Constructing mathematical models of various unit devices in a steam power system based on various thermodynamic models of water and steam; wherein, the mathematical model of each type of unit device includes: at least one set of set input parameters and at least one set of set output parameters corresponding to at least one set of set input parameters, and the mathematical model of each type of unit device is used to calculate the value of a corresponding set of output parameters according to the value of one set of input parameters; Determining all target unit devices and connection relationships included in the target steam power system to be simulated, as well as all target types to which all target unit devices belong; Determining the simulation calculation order of each target unit device in the target steam power system based on the connection relationship; According to the obtained simulation calculation order, using the mathematical models of unit devices of each target type and the values of the set input parameters of each target unit device to simulate and calculate each target unit device, obtaining the values of the corresponding set output parameters of each target unit device, until all target unit devices are simulated and calculated, obtaining the full-process simulation model of the target steam power system.

2. The construction method according to claim 1, characterized in that, The thermodynamic properties include: enthalpy of water, entropy of water, enthalpy of steam, entropy of steam, density of steam, saturation pressure of water, saturation temperature of water, saturation pressure of steam, saturation temperature of steam, temperature of water, and temperature of steam.

3. The construction method according to claim 2, characterized in that, The constructing various thermodynamic models of water and steam based on various thermodynamic properties of water and steam includes: Calculating the enthalpy of water according to the temperature and pressure of water; calculating the entropy of water according to the temperature and pressure of water; calculating the enthalpy of steam according to the temperature and pressure of steam; calculating the entropy of steam according to the temperature and pressure of steam; calculating the density of steam according to the temperature and pressure of steam; calculating the saturation pressure of water or steam according to the temperature; calculating the saturation temperature of water or steam according to the pressure; calculating the temperature of water according to the pressure and enthalpy of water; calculating the temperature of steam according to the pressure and enthalpy of steam; calculating the temperature of water according to the pressure and entropy of water; calculating the temperature of steam according to the steam pressure and entropy.

4. The method according to claim 3, characterized in that The various types of unit devices include: header type unit devices and non-header type unit devices; The header type unit devices include: water / steam header, fuel header, and power header; The unit devices of the header type unit devices include: steam boiler, steam turbine, pump, desuperheater, deaerator, generator set, pump set, drive set, heater, cooler, heat exchanger, flash tank.

5. The method according to claim 4, characterized in that When the unit device is a steam boiler, steam turbine, or pump, the corresponding mathematical model of the unit device is generated based on the material balance model, energy balance model, and efficiency calculation model of the unit device; When the unit device is any one of the following: desuperheater, deaerator, generator set, pump set, drive set, heater, cooler, heat exchanger, the corresponding mathematical model of the unit device is generated based on the material balance model and energy balance model of the unit device; When the unit device is a flash tank, the corresponding mathematical model of the unit device is generated based on the material balance model, energy balance model, and phase equilibrium model of the unit device; When the unit device is a water / steam header, the mathematical model corresponding to the unit device is generated based on the material balance model of the unit device; When the unit device is a fuel header or an electric power header, the mathematical model corresponding to the unit device is generated based on the energy balance model of the unit device.

6. The method according to claim 5, characterized in that, The material balance model of the unit device is constructed based on the material balance principle; The energy balance model of the unit device is constructed based on the law of conservation of energy and according to one or more thermodynamic property models of the enthalpy of water, the enthalpy of steam, the temperature of water, and the temperature of steam; The efficiency calculation model of the unit device is constructed according to the chemical engineering principles and chemical engineering thermodynamics equations of the unit device and according to a variety of thermodynamic properties including the enthalpy of water, the entropy of water, the enthalpy of steam, the entropy of steam, the density of steam, the saturation pressure of water, the temperature of water, and the temperature of steam.

7. The method according to claim 4, wherein Determining the simulation calculation order of each target unit device in the target steam power system based on the connection relationship includes: According to the connection relationship of the target steam power system, determining the simulation calculation order of the water / steam header in the forward order or reverse order of the water / steam flow direction into the water / steam header, and correlating the material balance input and output parameters of the steam header and the output or input related parameters of each target unit device connected thereto; Determining the simulation calculation order of the fuel header in the forward order or reverse order of the fuel flow direction into the fuel header, and correlating the energy balance input and output parameters of the fuel header and the output or input related parameters of each target unit device connected thereto; Determining the simulation calculation order of the electric power header in the forward order or reverse order of the current flow direction into the electric power header, and correlating the energy balance input and output parameters of the electric power header and the related output or input parameters of each target unit device connected thereto; Determining the simulation calculation order of various headers and each target unit device directly connected to various headers according to the calculation order of the water / steam header, fuel header, and electric power header; According to the simulation calculation order of various headers and each target unit device directly connected to various headers, determining the simulation calculation order of other target unit devices in the forward order or reverse order of the process flow to obtain the simulation calculation order of each target unit device in the target steam power system; wherein, the forward order or reverse order is determined according to the actual calculation requirements.

8. The method according to claim 7, characterized in that, According to the obtained simulation calculation order, simulating each target unit device by using the mathematical model of each target type unit device and the value of the input parameter set for each target unit device to obtain the value of the output parameter set corresponding to each target unit device until all target unit devices are simulated, to obtain the full-process simulation model of the target steam power system, including: According to the process flow of the target steam power system, based on the material balance of each water / steam header, correlating the input and output of each water / steam mass flow of each water / steam header with the output or input of the water / steam mass flow of each target unit device connected thereto respectively; According to the process of the target steam power system, based on the energy balance of each fuel header, the input and output of each energy flow of each fuel header are respectively associated with the energy flow output of each target unit device connected thereto or the energy flow input parameters of each target unit device connected thereto; According to the process of the target steam power system, based on the energy balance of each power header, the input and output of each energy flow of each power header are respectively associated with the energy flow output of each target unit device connected thereto or the energy flow input parameters of each target unit device connected thereto; After the association of each water / steam header, each fuel header and each power header is completed, a full-process simulation model of the target steam power system is obtained.

9. The method according to claim 1, wherein After obtaining the full-process simulation model of the target steam power system, it further includes: Calculating the water consumption, fuel consumption and power consumption of the target steam power system according to the full-process simulation model; Calculating the fuel and power cost of the target steam power system according to the unit price of water, the unit price of fuel, the unit price of power, the water consumption, the fuel consumption and the power consumption of the target steam power system; Calculating the carbon emission of the target steam power system according to the carbon emission factor, the water consumption, the fuel consumption and the power consumption of the target steam power system.

10. A system for constructing a full-process simulation model of a steam power system, comprising: A memory and a processor, the memory is used to store an executable program; The processor is used to read and execute the executable program to implement the method for constructing a full-process simulation model of the steam power system according to any one of claims 1-9.

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